Export just shadows

Box

And roughly the same cluster of shapes with transparent texture and some edges and faces on and off.

I must admit, I'm lost as to where this is going and as such am off to bed.

BTW the transparent png texture that I used was discussed recently in this thread.
http://sketchucation.com/forums/viewtopic.php?f=15%26amp;t=60086

jeff hammond

@box said:

I must admit, I'm lost as to where this is going and as such am off to bed.

going nowhere.. it's already been found out @steve was following ronen's tutorial improperly as there was no fancy transparent exports going on in there.

i feel like you think i'm trying to arm wrestle over something when i'm just sharing ideas to the general community.

using a renderer will allow you to get the shadows which fall on faces while still keeping the rest of the object transparent.. or block out shadows which shouldn't be visible.

another use is for very high quality shadow work in large exports.. here's an example of that:
(6000px wide -- view at full size)

Dropbox - 404

(dl.dropboxusercontent.com)

(8MB download)

Box

God no Jeff, no arm wrestling.
Just a bit confused by the complexity of the whole shadows thing.

jeff hammond

@box said:

God no Jeff, no arm wrestling.
Just a bit confused by the complexity of the whole shadows thing.

heh.. well it can get kind of complicated depending on what the final need of the shadows is.

if i wanted to do some post processing on the shadows then lay them on the geometry, i couldn't really just use transparent texture:

this scene:

transparent texture w/ transparent background:

combined: it doesn't work out right.. there should be some shadows on the faces and some places on the ground which don't have shadows

for reference, the shadows should look like this with every area not draped with a shadow being transparent:

reference#2 ..hidden line mode

EDIT- upon rereading, i'm pretty sure john said the quickest and easiest method.. that being- export the hidden line view then use preview.app's instant-alpha (at least on mac) to get rid of the geometry which still shows up.. it takes like 4 seconds to do

suSteve

Thanks Jeff

I went with white objects and in PS I set the layer to multiply. Works well overall

<edit> yes I was following the tutorial incorrectly. Nice to find out this stuff though

Thanks again

Dave R

I guess it's too late but here's the tutorial from May of 2011 I did showing exporting only shadows and using them to create soft shadows.

Steve, was it setting the layer to Multiply that did the trick?

suSteve

Sorry Dave, only just seen this. Yes setting to multiply but the missing part was to turn off the transparency in options before export.

Dave R

Ah....

Since I always use a white background for the shadow-only export, I never bother with making the background transparent so I didn't think to bring that part up.

suSteve

It's transparency on when you export the model and then off for the shadows. Easy to miss as the options are sticky.

Thanks again

Dave R

Actually I don't usually turn transparency on at all. Either I want the background if there is one or it doesn't come into play at all because the background is white. When combining images using Multiply, the white background acts as transparent anyway.